Process of purifying and clarifying raw sugar-cane juices.



35 i dry lime in the form of milk of lime. It is UNITE 1% ROBERT E.GORDON. OF WALLACEBURG. ONTARIO, CANADA.

PROCESS OF PURIFYING AND OLARIFYING RAW SUGAR-CANE JUICES.

No Drawing.

Specification of Letters Patent.

Application filed March 31. 1913. Serial No. 758.081.

Patented Apr. 28. 1914:.

To all whom it may concern Be it knownthat I, ROBERT E. GORDON, a

subject of the King of Great Britain and 'Ireland, residing atVVallaceburg, in the Province of Ontario and Dominion of Canada, haveinvented certain new and use ful Improvements in Processes of Purifyingand Clarifying Raw Sugar-Cane Juices. oi which the following is aspecification.

The invention relates. to the manufacture of cane sugar and hasparticular reference to an improved process in which the raw juices arepurified and clarified prior toconcentration.

In carrying out my process I proceed as follows: The raw juices just asextracted from the, cane are first heated to the boiling point; they arethen cooled from 30 to 40; after which the precipitated impuritiessuchas albuminoids, gums, etc-are removed by decantation or filtration. The

solution is then limed, preferably by introducing milk of lime to anamount equal to 3% of dry lime; and immediately following this treatmentthe solution is carbonated to neutrality. The temperature is then raisedto'90 (1, the lime carbonate being still present, the effect being toproduce a slightly alkaline condition, due'to the decomposition of thelime compounds saccharites, and bicarbonates. Following this thesolution is filtered to remove impurities, the temperature of 90 C.being still maintained. The solution is next re-limed by theintroduction of approximately from l to of then re-carbonatcd to thepoint of neutrality; re-heated torestore the temperature to 90 0.; isfiltered; and finally treated by a small amount of sulturous acid,prete'ably in the form of gas, and operating mainly as a bleachingagent.

The essential feature of my improved process is, as I understand it, theremoval of albuminoids and other organic impurities by heat treatmentprior to the introduction oi lime into the solution. This avoids thedisooloring of the solution which would take place by the reaction ofthe lime upon said impurities if remaining in the solution, particularlywhere subjected to high temperatures. I have discovered that it is notnecessary to neutralize thenatural acid condition- 5 of the juices ifthe temperature is raised to 90 or higher immediately after extraction.Heretofore it has been deemed essential to add lime. or otherwise renderthe solution alkaline so as to prevent fermentation and the formation ofinvert sugar.

The treatment carried out as above set forth. results .in theelimination of impuritics and the clarification of the juices, so thatthe latter may be then concentrated and manufactured into white sugarwithout further purification.

What I claim as my invention is:

1. The process of pnrifying and clarifying raw sugar cane juices,comp-rising heating the juice as extracted from the cane to atemperature above 90 C. to precipitate impurities. removing theprecipitated impurities, liming at low temperature, carbonatiug. raisingthe temperature to above 90 while the carbonate of lime is present inthe solution, removing precipitated impurites, re-liming,re-carbonating, raising the temperature to above 90 (1., removingprecipitated impurities, and neutralizing the alkalinity of thesolution.

2. The process of purifying and clarifying raw sugar cane juices,comprising heating the raw juices as extracted from the cane to atemperature above 90 (1.. cooling, removing precipitated impurities,liming, carbonating. raising the temperature to above 90 (1, and againremoving precipitated impurities. t

3. The process of purifying and clarifying raw sugar cane juices.comprising the heating of the raw sugar juice as extracted from the caneto a temperature above 90 0.. cooling and removing precipitatedimpurities. and subsequently treating the solution to alternate limingand carbonation to re move further impurities.

4. The process oi purifying and clarifylug raw sugar cane juices.comprising the heating of the same immediately following extraction fromthe cane to a temperature above 90 C, removing precipitated impurities.and subsequently refining by liming and carbonation.

a"). The process of purifying and clarifying raw sugar cane juices,comprising the heating of said juices immedi' traction to nten'ipei'ulurc above 90" C qulckly cooling the solution preclpitatedimpurities,

figpurifying by liming, carb tlon, nmmtalmng a high temperature afterthe first carbonation.

Holy after eX- ROBERT E. GORDON.

removing the and subsequently onation and filt Witnesses JAMES 1. BARRY,DELBI'IR'J CoLLms.

